The Mysterious Masked Owl
by Sarah Lloyd OAM
The Tasmanian Masked Owl's silent flight, infrequent calling and highly mobile nature makes it one of our most mysterious forest birds. Being nocturnal and with a huge home range of about 2000 hectares, Masked Owls are highly unlikely to be found during field surveys, so scientists are trying a different approach. They’re using specially trained dogs to sniff out piles of pungent pellets under their roosting or nesting trees. These pellets can reveal a lot about the lives of these formidable hunters.
Most birds expel pellets in a process akin to vomiting. Pellets contain the bits of food they can’t digest such as bones, feathers, hair or invertebrate remains. Studies of Masked Owl pellets indicate their preference for small mammals, especially rats, mice and rabbits, but also native animals like bandicoots, birds and possums. These efficient hunters kill their prey with their raptorial—grasping—talons.
Owls have three remarkable traits that enable them to function in the dark. Their eyes absorb 100 times more light than human eyes so for them the darkest night is like early dusk and dusk is like bright daylight. Their hearing is equally acute. They have large ear openings on their facial disc and flaps of skin on each side of their head. These features direct the sounds to the inner ears, amplify the sounds and enhance the birds' ability to determine direction. Owls have large broad wings and uniquely structured feathers that means they can move slowly and silently through the forest. The leading edge of their wing feathers have comb-like serrations that break up the turbulent air that typically creates the swooshing sound. The smaller streams of air are further dampened by the feathers' velvety texture and by a soft fringe on the wing's trailing edge.
The Tasmanian Masked Owl - along with Tasmanian Devil and Wedge-tailed Eagle - is an 'apex predator', a species at the top of the food web that preys on other animals but has no predators itself. They are naturally rare and vulnerable to persecution because they often come in conflict with humans, e.g. by taking livestock. However, they are extremely important because they control populations of introduced pests such as rats and rabbits whose numbers can reach plague proportions; rabbit plagues can strip the land of vegetation leading to massive erosion. Predators also remove old, injured, sick, or very young animals so they help to keep populations healthy. Apex predators are also important in controlling populations of 'mesopredators' such as feral cats and foxes.
The Tasmanian Masked Owl inhabits mostly lowland forests like those that extend from Reedy Marsh to Birralee. Some residents (myself included) have been lucky enough to have a memorable encounter with this elusive bird.
Footnote: several pellets/scats have been found at Westbury Reserve during recent outings. Last week one was confirmed as the pellet of the Tasmanian Masked Owl by a researcher at Queen Victoria Museum and Art Gallery, Launceston.
The pellet was 'most definitely' masked owl, with a Starling's scull and beak, and numerous scales probably from a blotched bluetongue.
Page URL: https://www.disjunctnaturalists.com/westbury/masked-owl.htm